Why you Need to Use Aluminum Copper Welding Tables for Stainless Steel Welding

There are various types of welding tables available for a wide range of jobs that utilize a variety of different metals. Important elements to consider are the material the top is made of, and the design of the table.

The most popular tops for welding tables in professional workshops areAluminum Copper | Welding Table carbon steel and several aluminum alloys. Your choice will depend on the metal (or metals) you and your employees will be working with. If you are working with carbon steels (including mild steel that, by definition contains between 0,15 and 0,35 percent carbon) then a carbon steel top is ideal. But if you are working with stainless steel, a welding table with an aluminum-copper alloy top will be a much better option. If you work with both types of metal, it’s best to have designated tables with a suitable top for each.

There are different types of stainless steel, but one thing they have in common is a percentage of the metal element chromium, that gives the metal its shiny appearance and prevents it from rusting. To be classified as stainless steel, metal must contain at least 10 percent chromium, but it often contains more.

Even though you can use the same welding processes when working with carbon steel and stainless steel, the latter is a lot more difficult to work with than carbon steels and it is a lot more expensive, largely because of its chromium content.

Aluminum and copper are both soft, non-ferrous metals. An aluminum-copper alloy is non-ferritic (containing no iron), yet sufficiently hard to form a safe surface or base for the professional processing and welding of stainless steel.

Benefits of Using an Aluminum-Copper Welding Table for Stainless Steel

For quality stainless steel processing it is essential that all ferritic materials are avoided. If a ferritic material like carbon steel is used, any scratches on the surface of the welding table, or adhesion to the stainless steel work piece, can cause corrosion and pitting.

A suitable aluminum-copper alloy will have high tensile strength, with a low surface hardness that won’t cause any ferritic scratches or pitting. Additionally, the surface has high thermal conductivity that prevents spatter from attaching to the welding table surface, and potentially risking damage to the work piece.

A good quality aluminum-copper alloy welding table will incorporate the best possible design features, including a clamping system and rails that are also non-ferritic.

Design Features to Look for When Buying Aluminum-Copper Alloy Welding Tables

All Forster welding tables feature T-slot tops that allow for 3D positioning and clamping of work pieces. This means that the table surface is only partially covered and parts of the work piece can be positioned so that they stick out of the otherwise vertical surface, enabling welders to access critical areas and every possible angle on the work piece. Not only does this make the working process easier and quicker, but fewer clamping elements are needed, and T-slot positions are further protected from welding spatter.

The best designs incorporate modular rails that are interchangeable and enable welders to work with absolute accuracy and produce the best quality work possible. Clamping plungers are made of bronze (which is also a copper alloy) and additional clamping elements and accessories, including copper rails, are available to extend and reinforce structures.

Contact us online or via email for more information about Forster welding tables for quality stainless steel welding.

The Top Tips for Welding Copper

Copper is a soft, non-ferrous metal that can be easily bent, cut, shaped and joined using several welding processes. While it is often used to make decorative household and architectural items, it is an excellent conductor of electricity and heat, and so is widely used in the electrical industry, while copper pipe, valves and other fittings are commonly used for plumbing.

Since it is ductile and highly malleable, copper is also used as the major element in hundreds of different alloys, including brass, bronze, and nickel copper. The most common alloying elements used for copper alloys are aluminum, nickel, zinc, tin, and silicon.

Because pure copper is too ductile to be successfully machined, small quantities of other elements are added to the various alloys to improve machinability, as well as to deoxidize the metal, make it more resistant to corrosion, improve its mechanical properties, and improve its response to heat treatments. In all there are more than 300 copper alloys available commercially.

Joining Copper to Copper or to Copper Alloys

welding-copperCopper and most copper alloys can be successfully joined using welding, brazing or soldering processes. The exact process chosen depends largely on whether you are welding pure copper or an alloy. If you are welding an alloy, the alloy elements will determine which process is used, as well as all the other factors one takes into account when welding, including filler material used.
Of course, the different welding and related processes require different tools and techniques, and it’s important to learn the skills required for which process you need to use.

Soldering, which is one of the earliest methods used to join metal, involves heating filler metal (in the form of a filler wire) so that it melts and fills joints. Soft soldering is the simplest process, and the one commonly used in and around the home to repair small metal items. It is also the method used by plumbers to join and repair copper pipe and copper fittings.
You can use an inexpensive soldering iron or a blowtorch with a suitable flux for soft soldering. Hard soldering involves heating the filler materials to a much higher temperature, so the joint will be a lot stronger than other soldered joints. The filler material is different and usually contains silver, so the technique is often referred to as silver brazing. However, true brazing is executed at an even higher temperature.

Brazing is essentially a technique similar to soldering, and it utilizes the same sort of filler material (wire or a brazing rod) used for soldering. Joints need to be very closefitting so that capillary action can draw the filler metal between the pieces of copper being joined. Even though temperatures used must be considerably higher than those required for soldering, the base metal mustn’t be heated to melting point.
Used extensively for plumbing work, brazing may also be used to join different types of metal as well as metal work pieces that are different thicknesses.

Welding, or more accurately arc welding, incorporates a number of different more specific techniques. Generally, the welding processes that utilize shielding gases are preferred, though shielded metal arc welding (SMAW) which is also commonly referred to as manual metal arc (MMA) welding can be used for applications that are not critical. It is a useful method for a variety of copper alloy thicknesses, especially since covered electrodes for welding copper alloys using SMAW are available in a wide range of standard sizes.

The shielding gases normally used for welding copper and copper alloys are argon and helium, or mixtures of the two – for either gas metal arc welding (GMAW), gas tungsten arc welding (GTAW), or plasma arc welding (PAW) which is particularly popular for welding copper alloys.
Generally argon is preferred if the copper or copper alloy is welded manually and either has a relatively low thermal conductivity, or is less than 3.3 mm (0.13 in) thick. Helium or a helium (75 percent) argon mix is preferred for machine welding thin sections, or manual welding of thicker sections. This mixture is also recommended for thicker metal or copper that has a high thermal conductivity.

Other top tips for arc welding copper include:
• Whenever possible use the flat position for arc welding copper.
• GTAW and SMAW can be used for welding in other positions, including overhead.
• If welding in vertical and overhead positions using pulsed power and small-diameter electrodes, GMAW may be used with some copper alloys.
• Thermal expansion of copper and its alloys, as well as its higher thermal conductivity, do result in greater weld distortions than when welding mild steel.
• To minimize distortion and warping, welders need to focus on correct preheat processes and tack welds, as well as following proper welding sequences.

Properties of Copper and its Alloys to be Aware of When Welding

Whichever welding process is used to join copper and its alloys, it is important to give attention to the properties that make the welding of copper different to the welding of carbon steels. For example, copper and copper alloys, when molten, are very fluid, and they have:
• High thermal conductivity
• High electrical conductivity
• A high thermal expansion coefficient that is about 50 percent higher than carbon steel
• A relatively low melting point
• Hot short that results in some alloys becoming brittle at high temperatures
• Strength that is largely due to cold working

The melting point of copper and its alloys is hugely variable, but it is at least 1,000 °F or 538 °C lower than the melting point of carbon steel. Also, copper doesn’t exhibit the same sort of heat colors seen when steel is welded, and when it melts its fluidity is much greater.

The Copper Development Association (CDA) Inc. that has established an alloy designation system widely used throughout North America, has a huge amount of information about welding copper and copper alloys for anyone wishing to learn more.

The Evolution of Welding [Infographic]

Welding is a fundamental part of almost every industry and product in today’s world. Some of the first welding processes we’re being utilized before iron was even discovered as a useful material, today there are many different popular welding processes for all types of metals and fabricaton.

Our timeline below begins in the “Bronze Ages” and shows all of the fundamental innovations in welding up until 1959, though there are many new technologies and processes being developed even today! Check out our infographic below to learn more.

The Evolution of Welding

Evolution of Welding Infographic | Forster America

Click the Infographic to see the Full-size Version!



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